A collapsible electronic device such as a portable telephone or a laptop computer includes, for example, a main body part including ten-keys or the like and a lid body part including a liquid crystal display or the like. Further, a hinge apparatus is provided at a connecting area between the main body part and the lid body part for rotating (oscillating) the lid body part relative to the main body part.
A hinge apparatus used for the above-described type of electronic device is disclosed in Patent Document 1. The hinge device for the electronic device disclosed in Patent Document 1 is a so-called double shaft type hinge apparatus. With the double shaft type hinge apparatus, the lid body part can be rotated 180 degrees about a first rotation shaft relative to the main body part. In addition, the main body part can be rotated 180 degrees about a second rotation shaft relative to the lid body part. Therefore, as a whole, the lid body part can be rotated 360 degrees relative to the main body part.
Further, the hinge apparatus disclosed in Patent Document 1 has a cam mechanism and a gear mechanism integrally provided therein. By providing the cam mechanism, a toggle is generated when the lid body part is positioned having a predetermined rotation angle relative to the main body part, to thereby retain the lid body part. Accordingly, visibility of the liquid crystal display or the like can be improved.